Address HIDL review comments

Fixes: 127852175

Test: builds
Test: hidl-gen -L hash -r android.hardware:hardware/interfaces android.hardware.biometrics.face@1.0
      hash added to current.txt
Test: make -j56 VtsHalBiometricsFaceV1_0TargetTest

Change-Id: I4a8b6db5824a686ec742ed826ff26e721ff26dc8
4 files changed